#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10, M = 2e5 + 10;
int n, m, tot = 1, nbs[N], ans;
int dfn[N], low[N], t, cnt, s[N];
stack<int> st; bool in_st[N];
struct edge
{
	int ed, next;
}b[M << 1];
void add(int u, int v)
{
	b[++ tot] = {v, nbs[u]}, nbs[u] = tot;
}
void tarjan(int x, int last)
{
	dfn[x] = low[x] = ++ t;
	st.push(x), in_st[x] = 1;
	for (int i = nbs[x]; i; i = b[i].next)
	{
		int j = b[i].ed;
		if (j == last) continue;
		if (!dfn[j]) tarjan(j, x), low[x] = min(low[x], low[j]);
		else if (in_st[j]) low[x] = min(low[x], low[j]);
	}
	if (dfn[x] == low[x])
	{
		int y;
		++ cnt;
		do
		{
			y = st.top();
			st.pop();
			in_st[y] = 0;
			s[cnt] ++;
		} while (x != y);
	}
}
int main()
{
	cin >> n >> m;
	for (int i = 1, u, v; i <= m; i ++ )
		cin >> u >> v, add(u, v), add(v, u);
	for (int i = 1; i <= n; i ++ )
		if (!dfn[i]) tarjan(i, 0);
	for (int i = 1; i <= cnt; i ++ )
		ans = max(ans, s[i]);
	cout << ans;
	return 0;
}